THE BEMBICENE WASPS 13 



further domiciles any more than a chick returns to its 

 egg-shell. 



In the following year we took up a diligent watch early 

 in June for this pretty phenomenon. Our expectations 

 waned with long waiting, until we gave up all hope of seeing 

 the frolic again. But on July 4 we were surprised by the 

 outburst of wasps, as sudden as before. The cool months 

 of May and June had probably retarded their emergence 

 until this late date. Even this hypothesis seems almost in- 

 credible when we consider that they came from the eggs 

 laid by many different mothers of the previous year from 

 June to September, and that even their nests, which remain 

 open until the larva is ready to pupate, were closed at widely 

 different periods; yet we can now imagine no explanation 

 for the phenomenon other than that the wasps which had 

 come to their maturity simultaneously, or had been lying 

 dormant ready to emerge at the fight conditions, had all 

 responded to the dazzling sunshine and the rising tempera- 

 ture of this bright morning and had all dug their way 

 straight out into the light, to mingle in this first social frolic 

 or dance. None of the characteristic nesting holes of Bem- 

 bix could be seen, but the clear-cut, vertical holes by which 

 they had emerged were even more numerous than in the 

 previous year. It was very noticeable too that the group 

 was limited to precisely the areas where the mothers had 

 nested during the previous few years, and where also the 

 sun-dance of the last year had occurred. Thus, for genera- 

 tion after generation, they live and reproduce in the spot 

 where they are born. 



Strange indeed is the constancy of instinct in this danc- 

 ing performance, which they are never taught and for 

 which they have no further use; nevertheless it occurs year 

 after year with each generation, and is in all details the 

 same. In this the second year we were alert to ferret out 



